(Beaverton, Oregon) - An odd weather anomaly has been happening in Beaverton lately, surprising and puzzling many in the middle of the night. A small patch – and only a small patch – has been snowing in the wee hours, leaving a thin layer of snow, while nothing around for miles has any sign of the frosty stuff.

At the Beaverton Central MAX station, off Canyon Road, the MAX station itself has gotten a bit of it. But mostly an area about 60 feet in diameter, just in back of the 24 Hour Fitness entrance, has been covered in the white stuff. It seems to center around the brick courtyard just south of the tracks, while the waiting benches and tracks themselves are completely dry.

Even some of the landscaping and a small piece of the parking lot has received the fluffy visitations, but aside from that – nowhere else in the vicinity.

The 24 Hour Fitness is at the bottom of one high-rise building, there is a parking garage next to it, and another real estate building next to that of about equal height. None of the walkways between the buildings contain any hint of snow, and neither do the streets around the area.

Nighttime staff at the 24 Hour Fitness front desk said it has been a visible light dusting – coming down in what seems a mysterious snow vortex.

Even curiouser, it starts about the same time every night: around 1 or 2 a.m.

Meanwhile, everything else is dry.

What's behind this weather anomaly? Is it a product of the freezing fog we've had in the Portland area lately?

Steve Pierce, president of the Chapter of the American Meteorological Society (AMS), said he really didn't know for sure, but he had a few guesses.

“There is a similar situation to this near Intel Corp. in Beaverton,” Pierce said. “Air conditioners and heat pumps emit quite a bit of moisture with their fans when it is cold outside. This moisture then condenses, freezes and becomes either ice or snow and falls back to the ground. Dense fog can also create this same result. I am pretty sure this is coming from a nearby source of moisture rather than it being heat pumps, fog. etc. A heavily populated area of vehicles may also account of this (as noted by the parking garage in the background). Just a thought.”

It turns out Pierce was more than a little correct – and this was not the only spot in Oregon where such a meteorological oddity was taking place. KATU Channel 2 found an area in Silverton with even more dramatic results.

A section of the town is also covered in white – but a somewhat larger stretch of road.

KATU said this is coming from steam from a nearby plant, which is then frozen in the air and freezes once it hits the ground in the immediate area - like snow, but not quite.

KATU Meteorologist Rhonda Shelby called it “radiation frost.” It comes from the ground being so much colder than other spots that nearby moisture sources freeze there and piles up.

If you look closely at the buildings surrounding the MAX station, some of these are also emitting steam into the air from various spots.